I own Blender Game Kit 2, and I must say, one of the best birthday presents I have ever received.

Blender Game Kit 2 has GLSL stuff, the first book was pretty much all MultiTexture. You can't make a good looking game (modern standards) with OpenGL without GLSL, so the book would be a good investment.

"Along with 'Antimatter,' and 'Dark Matter,' we've recently discovered the existence of 'Doesn't Matter,' which appears to have no effect on the universe whatsoever." -The 5th Wave